I found the collection of information I am planning to use.

http://www.nlm.nih.gov/medlineplus/adrenalglanddisorders.html

You will need to click "Managing Adrenal Insufficiency".  It is in very simple terms in explaining how the the adrenal gland is not working properly and what happens to the body without the needed hormones.  I also like it because it will be easy to say, "If he has fever or injury, etc, this is what is happening to his body", or"If he starts to vomit, this could be happening".  I think it will help the teacher make a pretty fair assessment of may be going on and what the next action should be.  Additionally, I like that it does not go into the whole issue of excess androgens.  It is just not relevant and I would rather not get into that unless it is necesarry.

Thanks to all of you e-mailed me and posted here.  I will be using many of your thoughts and suggestions on my cover letter.  Now, if only his Mommy can get prepared to LEAVE him!  Waaaah!  :-)